| Message ID | 20231222101707.6921-1-kundan.kumar@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] block: skip start/end time stamping for passthrough IO | expand |
On Fri, 22 Dec 2023 15:47:07 +0530, Kundan Kumar wrote: > commit 41fa722239b4 ("blk-mq: do not include passthrough requests in I/O > accounting")' disables I/O accounting for passthrough requests. Since tools > like 'iostat' do not show anything useful for passthrough I/O, it's > wasteful to do start/end time-stamping. So do away with that. > > Avoiding the time-stamping improves the I/O performance by ~7% > > [...] Applied, thanks! [1/1] block: skip start/end time stamping for passthrough IO commit: 8e6e83d77227d9ba39e0c7b50693f1b4f8728006 Best regards,
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 1ab3081c82ed..a676e116085f 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -830,6 +830,12 @@ void blk_mq_end_request_batch(struct io_comp_batch *ib); */ static inline bool blk_mq_need_time_stamp(struct request *rq) { + /* + * passthrough io doesn't use iostat accounting, cgroup stats + * and io scheduler functionalities. + */ + if (blk_rq_is_passthrough(rq)) + return false; return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS | RQF_USE_SCHED)); }
commit 41fa722239b4 ("blk-mq: do not include passthrough requests in I/O accounting")' disables I/O accounting for passthrough requests. Since tools like 'iostat' do not show anything useful for passthrough I/O, it's wasteful to do start/end time-stamping. So do away with that. Avoiding the time-stamping improves the I/O performance by ~7% Signed-off-by: Kundan Kumar <kundan.kumar@samsung.com> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> --- Changes compared to v1: - Modified commit description. - Made code cleaner with bit of separation. include/linux/blk-mq.h | 6 ++++++ 1 file changed, 6 insertions(+)